I don't use a proxy server, so I've never had occasion to ask this question myself, however I don't believe there is any place in the Outpost GUI that displays any proxy/socks settings, except for the Outpost Update settings which lets you specify to use a proxy server for connecting to the agnitum server for updates to Outpost.

I believe proxy settings are only specified within the programs that you allow to connect to the internet. For instance, Internet Explorer has a dialog that lets you specify proxy settings.

You may want to confirm my responses over at the Outpost forum. Or just check out the forum anyway!. I heartily recommend it as a great place to learn about Outpost and internet/LAN connectivity.